1. Field of the Invention
The present invention relates to a compact optical unit. In particular, the present invention relates to a compact optical unit which can be inserted into a channel in an endoscope.
2. Description of Related Art
For a compact confocal optical system which is used in an endoscope, it is possible to categorize two systems generally. One is a side-view optical system in which a longitudinal direction of its probe and a perspective direction do not coincide. The other is a direct-view optical system in which a longitudinal direction of its probe and a perspective direction coincide. However, when a side-view compact confocal optical system probe is used in a channel in a direct-view endoscope, there is a problem in that it is difficult to specify a scope of observation in the confocal optical system. On the other hand, when a direct-view compact confocal optical system probe is used in a channel in a direct-view endoscope, it is possible to see a position of the confocal optical system and a perspective range easily by an objective lens in the endoscope. Also, it is possible to adjust the perspective range of the confocal optical system to any object. Some of the direct-view compact confocal optical system probes which can be inserted to a channel in the endoscope are publicly known (see following patent document).
Japanese Unexamined Patent Application, First Publication No. 2000-171726 (pages 2 to 7, FIG. 1)